Part 1

OVERHAUL
1. REMOVE VALVE LIFTER
a. Remove the valve lifter and adjusting shim.

HINT: Arrange the valve lifters and shims in the correct order.

2. REMOVE INTAKE VALVE
a. Using SST, compress the compression spring and re move the 2 keepers.
SST 09202-70020 (09202-00010)
b. Remove the spring retainer, compression spring, valve and spring seat.

HINT: Arrange the valves, compression springs, spring seats and spring retainers in the correct order.

3. REMOVE EXHAUST VALVE
a. Using SST, compress the compression spring and re move the 2 keepers.
b. Remove the spring retainer, compression spring, valve and spring seat.

HINT: Arrange the valves, compression springs, spring seats and spring retainers in the correct order.

4. REMOVE VALVE STEM OIL SEAL
a. Using needle-nose pliers, remove the oil seal.

5. INSPECT CYLINDER HEAD SUB-ASSEMBLY
a. Clean the cylinder head.
1. Using a gasket scraper, remove all the gasket material from the cylinder block contact surface.

NOTICE: Be careful not to scratch the cylinder block contact surface.

2. Using a wire brush, remove all the carbon from the combustion chambers.

NOTICE: Be careful not to scratch the cylinder block contact surface.

3. Using a valve guide bushing brush and solvent, clean all the guide bushes.

4. Using a soft brush and solvent, thoroughly clean the cylinder head.

b. Inspect for flatness.
1. Using a precision straightedge and feeler gauge, measure the surfaces contacting the cylinder block and the manifolds for warpage.

Maximum warpage

c. Inspect the cylinder head for cracks.
1. Using a dye penetrant, check the combustion chamber, intake ports, exhaust ports and cylinder block surface for cracks. If the cylinder head is cracked, replace it.

6. INSPECT INTAKE VALVE
a. Clean the valves.
1. Using a gasket scraper, chip off any carbon from the valve head.
2. Using a wire brush, thoroughly clean the valve.

b. Using a micrometer, measure the diameter of the valve stem.
Valve stem diameter: 5.470 to 5.485 mm (0.2154 to 0.2159 inch)
If the diameter is greater than the maximum, replace the valve and guide bushing.

c. Check the valve face angle.
1. Grind the valve enough to remove pits and carbon.
2. Check that the valve is ground to the correct valve face angle.
Valve face angle: 44.5°
If the valve face is worn, replace the valve.

d. Check the valve head margin thickness.
Standard margin thickness: 1.0 mm (0.039 inch)
Minimum margin thickness: 0.5 mm (0.020 inch)
If the margin thickness is less than the minimum, replace the valve.

e. Check the valve overall length.
Standard overall length: 94.80 to 95.30 mm (3.7323 to 3.7520 inch)
Minimum overall length: 94.55 mm (3.7224 inch)
If the overall length is less than the minimum, replace the valve.

f. Check the surface of the valve stem tip for wear.
If the valve stem tip is worn, resurface the tip with a grinder or replace the valve.

NOTICE: Be careful not to grind off more than the minimum.

7. INSPECT EXHAUST VALVE
a. Clean the valves.
1. Using a gasket scraper, chip off any carbon from the valve head.
2. Using a wire brush, thoroughly clean the valve.

b. Using a micrometer, measure the diameter of the valve stem.
Valve stem diameter: 5.465 to 5.480 mm (0.2152 to 0.2157 inch)
If the clearance is greater than the maximum, replace the valve and guide bushing.

e. Check the valve overall length.
Standard overall length: 94.85 to 95.35 mm (3.7342 to 3.7539 inch)
Minimum overall length: 94.60 mm (3.7244 inch)
If the overall length is less than the minimum, replace the valve.

8. INSPECT INNER COMPRESSION SPRING
a. Using steel squares, measure the deviation of the spring.
Maximum deviation: 2.0 mm (0.079 inch)
If the deviation is greater than the maximum, replace the spring.

b. Using a vernier caliper, measure the free length of the spring.
Free length: 54.05 to 54.15 mm (2.1279 to 2.1319 inch)
If the free length is not as specified, replace the spring.

c. Using a spring tester, measure the tension of the valve spring at the specified installed length.
Installed tension: 204 to 226 N (20.8 to 23.0 kgf, 45.9 to 50.7 lbs.) at 35.04 mm (1.3795 inch)
If the installed tension is not as specified, replace the valve spring.

9. INSPECT INTAKE VALVE GUIDE BUSH
a. Using a caliper gauge, measure the inside diameter of the guide bush.
Bush inside diameter: 5.510 to 5.530 mm (0.2169 to 0.2177 inch)
If the journal diameter is not as specified, check the oil clearance.
b. Subtract the valve stem diameter measurement (see step 6) from the guide bush inside diameter measurement.
Standard oil clearance: 0.025 to 0.060 mm (0.0010 to 0.0024 inch)
Maximum oil clearance: 0.08 mm (0.0031 inch)
If the clearance is greater than the maximum, replace the valve and guide bush (see steps 11 and 13).

10. INSPECT EXHAUST VALVE GUIDE BUSH
a. Using a caliper gauge, measure the inside diameter of the guide bush.
Bush inside diameter: 5.510 to 5.530 mm (0.2169 to 0.2177 inch)
If the journal diameter is not as specified, check the oil clearance.
b. Subtract the valve stem diameter measurement (see step 7) from the guide bush inside diameter measurement.
Standard oil clearance: 0.030 to 0.065 mm (0.0012 to 0.0026 inch)
Maximum oil clearance: 0.10 mm (0.0039 inch)
If the clearance is greater than the maximum, replace the valve and guide bush (see steps 12 and 14).

11. REMOVE INTAKE VALVE GUIDE BUSH
a. Gradually heat the cylinder head to approximately 80 to 100°C (176 to 212°F).

b. Using SST and a hammer, tap out the guide bush.
SST 09201-01055, 09950-70010 (09951-07100)
12. REMOVE EXHAUST VALVE GUIDE BUSH

a. Gradually heat the cylinder head to approximately 80 to 100°C (176 to 212°F).

b. Using SST and a hammer, tap out the guide bush.
SST 09201-01055, 09950-70010 (09951-07100)

13. INSTALL INTAKE VALVE GUIDE BUSH
a. Using a caliper gauge, measure the bush bore diameter of the cylinder head.

b. Select a new guide bush (STD or O/S 0.05).
If the bush bore diameter of the cylinder head is greater than 10.306 mm (0.4057 inch), machine the bush bore diameter to between 10.335 and 10.356 mm (0.4068 to 0.4077 inch).
If the bush bore diameter of the cylinder head is greater than 10.356 mm (0.4077 inch), replace the cylinder head.

HINT: Different bushes are used for the intake and exhaust.

Intake bush length: 34.5 mm (1.358 inch)

c. Gradually heat the cylinder head to approximately 80 to 100°C (176 to 212°F).
d. Using SST and a hammer, tap in a new guide bush to the specified protrusion height.
SST 09201-01055, 09950-70010 (09951-07100)
Protrusion height (H): 9.2 to 9.8 mm (0.362 to 0.386 inch)

e. Using a sharp 5.5 mm reamer, ream the guide bush to obtain the standard specified clearance (see step 9) between the guide bush and valve stem.

14. INSTALL EXHAUST VALVE GUIDE BUSH
a. Using a caliper gauge, measure the bush bore diameter of the cylinder head.

b. Select a new guide bush (STD or O/S 0.05).
If the bush bore diameter of the cylinder head is greater than 10.306 mm (0.4057 inch), machine the bush bore diameter to between 10.335 and 10.356 mm (0.4068 to 0.4077 inch).
If the bush bore diameter of the cylinder head is greater than 10.356 mm (0.4077 inch), replace the cylinder head.

HINT: Different bushes are used for the intake and exhaust.

Exhaust bush length: 40.5 mm (1.594 inch)

c. Gradually heat the cylinder head to approximately 80 to 100°C (176 to 212°F).
d. Using SST and a hammer, tap in a new guide bush to the specified protrusion height.
Protrusion height (H): 8.2 to 8.8 mm (0.323 to 0.346 inch)
SST 09201-01055 (09951-07100), 09950-70010

e. Using a sharp 5.5 mm reamer, ream the guide bush to obtain the standard specified clearance (see step 10) between the guide bush and valve stem.

15. INSPECT INTAKE VALVE SEAT
a. Using a 45° carbide cutter, resurface the valve seats. move only enough metal to clean the seats.

b. Check the valve seating position.
1. Apply a light coat of Prussian blue (or white lead) to the valve face.
2. Lightly press the valve against the seat. Do not rotate the valve.
c. Check the valve face and seat for the following:
1. If blue appears 360° around the face, the valve is concentric. If not, replace the valve.
2. If blue appears 360° around the valve seat, the guide and face are concentric. If not, resurface the seat.
3. Check that the seat contact is in the middle of the valve face and has the width below.
Width: 1.0 to 1.4 mm (0.039 to 0.055 inch)

If not, correct the intake valve seats as follows:
d. If the seating is too high on the valve face: Use 30° and 45° cutters to correct the seat.

e. If the seating is too low on the valve face: Use 60° and 45° cutters to correct the seat.

f. Handrub the valve and valve seat with an abrasive compound.
g. After handrubbing, clean the valve and valve seat.